• Imaging Science in Dentistry
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• v.44 no.2
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• pp.121-128
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• 2014

Purpose: The present study was performed to compare the planning of implant placement based on panoramic radiography (PAN) and cone-beam computed tomography (CBCT) images, and to study the impact of the image dataset on the treatment planning. Materials and Methods: One hundred five partially edentulous patients (77 males, 28 females, mean age: 46 years, range: 26-67 years) seeking oral implant rehabilitation were referred for presurgical imaging. Imaging consisted of PAN and CBCT imaging. Four observers planned implant treatment based on the two-dimensional (2D) image data-sets and at least one month later on the three-dimensional (3D) image dataset. Apart from presurgical diagnostic and dimensional measurement tasks, the observers needed to indicate the surgical confidence levels and assess the image quality in relation to the presurgical needs. Results: All observers confirmed that both imaging modalities (PAN and CBCT) gave similar values when planning implant diameter. Also, the results showed no differences between both imaging modalities for the length of implants with an anterior location. However, significant differences were found in the length of implants with a posterior location. For implant dimensions, longer lengths of the implants were planned with PAN, as confirmed by two observers. CBCT provided images with improved scores for subjective image quality and surgical confidence levels. Conclusion: Within the limitations of this study, there was a trend toward PAN-based preoperative planning of implant placement leading towards the use of longer implants within the posterior jaw bone.

• Imaging Science in Dentistry
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• v.47 no.3
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• pp.199-207
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• 2017

Purpose: Evaluation of alveolar bone is important in the diagnosis of dental diseases. The periodontal ligament space is difficult to clearly depict in cone-beam computed tomography images because the reconstruction filter conditions during image processing cause image blurring, resulting in decreased spatial resolution. We examined different reconstruction filters to assess their ability to improve spatial resolution and allow for a clearer visualization of the periodontal ligament space. Materials and Methods: Cone-beam computed tomography projections of 2 skull phantoms were reconstructed using 6 reconstruction conditions and then compared using the Thurstone paired comparison method. Physical evaluations, including the modulation transfer function and the Wiener spectrum, as well as an assessment of space visibility, were undertaken using experimental phantoms. Results: Image reconstruction using a modified Shepp-Logan filter resulted in better sensory, physical, and quantitative evaluations. The reconstruction conditions substantially improved the spatial resolution and visualization of the periodontal ligament space. The difference in sensitivity was obtained by altering the reconstruction filter. Conclusion: Modifying the characteristics of a reconstruction filter can generate significant improvement in assessments of the periodontal ligament space. A high-frequency enhancement filter improves the visualization of thin structures and will be useful when accurate assessment of the periodontal ligament space is necessary.

• Imaging Science in Dentistry
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• v.53 no.4
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• pp.345-353
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• 2023

Purpose: The objective of this study was to propose a method for developing a clinical phantom to reproduce various diseases that are clinically prevalent in the field of dentistry. This could facilitate diverse clinical research without unnecessarily exposing patients to radiation. Materials and Methods: This study utilized a single dry skull, which was visually and radiographically examined to evaluate its condition. Existing lesions on the dry skull were preserved, and other relevant lesions were artificially created as necessary. These lesions were then documented using intraoral radiography and cone-beam computed tomography. Once all pre-existing and reproduced lesions were confirmed by the consensus of 2 oral and maxillofacial radiologists, the skull was embedded in a soft tissue substitute. To validate the process, cone-beam computed tomography scans and panoramic radiographs were obtained of the fabricated phantom. All acquired images were subsequently evaluated. Results: Most lesions could be identified on panoramic radiographs, although some sialoliths and cracked teeth were confirmed only through cone-beam computed tomographic images. A small gap was observed between the epoxy resin and the bone structures. However, 2 oral and maxillofacial radiologists agreed that this space did not meaningfully impact the interpretation process. Conclusion: The newly developed phantom has potential for use as a standardized phantom within the dental field. It may be utilized for a variety of imaging studies, not only for optimization purposes, but also for addressing other experimental issues related to both 2- and 3-dimensional diagnostic radiography.

• Archives of Plastic Surgery
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• v.39 no.5
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• pp.477-482
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• 2012

Background The bone graft for the alveolar cleft has been accepted as one of the essential treatments for cleft lip patients. Precise preoperative measurement of the architecture and size of the bone defect in alveolar cleft has been considered helpful for increasing the success rate of bone grafting because those features may vary with the cleft type. Recently, some studies have reported on the usefulness of three-dimensional (3D) computed tomography (CT) assessment of alveolar bone defect; however, no study on the possible implication of the cleft type on the difference between the presumed and actual value has been conducted yet. We aimed to evaluate the clinical predictability of such measurement using 3D CT assessment according to the cleft type. Methods The study consisted of 47 pediatric patients. The subjects were divided according to the cleft type. CT was performed before the graft operation and assessed using image analysis software. The statistical significance of the difference between the preoperative estimation and intraoperative measurement was analyzed. Results The difference between the preoperative and intraoperative values were $-0.1{\pm}0.3cm^3$ (P=0.084). There was no significant intergroup difference, but the groups with a cleft palate showed a significant difference of $-0.2{\pm}0.3cm^3$ (P<0.05). Conclusions Assessment of the alveolar cleft volume using 3D CT scan data and image analysis software can help in selecting the optimal graft procedure and extracting the correct volume of cancellous bone for grafting. Considering the cleft type, it would be helpful to extract an additional volume of $0.2cm^3$ in the presence of a cleft palate.

• The Journal of the Korean dental association
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• v.50 no.4
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• pp.196-202
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• 2012

Radiographic diagnosis of periapical lesions is based on many factors, including anatomical limitations such as thickness of the cortical bone; positioning of the apical abscess to the cortical bone; and is complicated by proximity to other anatomical structures and neighboring teeth. With conventional radiographs, these structures are often superimposed. Dental CBCT with its associated geometric accuracy offers accurate visualizations of the complex relationships and boundaries between teeth, related anatomical features, and their associated pathology. Its images also provide us internal tooth morphology, periodontal ligament space, the presence or absence of periapicl lesions in association wi th critical anatomical structures and maxillary sinus involement. Using 3 D imaging makes it easier for clinicians to detect, diagnosis, and develop highly effective treatment plans. Now, 4 cases of periapical and periodontal pathosis with CBCT images are to be presented including periapical abscess, furcation involvement, periapical pathosis involving maxillary sinus, and osteomyelitis. CBCT analyze specific area of interest and provides the highly detailed anatomical information. It also facilitates earlier and more accurate diagnosis, and treatment planning decisions and more predictable outcome.

• The korean journal of orthodontics
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• v.47 no.4
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• pp.222-228
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• 2017

Objective: To evaluate soft- and hard-tissue changes in the mandibular angle area after the administration of botulinum toxin type A (BoNT-A) injection to patients with masseteric hypertrophy by using three-dimensional cone-beam computed tomography (3D-CBCT). Methods: Twenty volunteers were randomly divided into two groups of 10 patients. Patients in group I received a single BoNT-A injection in both masseter muscles, while those in group II received two BoNT-A injections in each masseter muscle, with the second injection being administered 4 months after the first one. In both groups, 3D-CBCT was performed before the first injection and 6 months after the first injection. Results: Masseter muscle thicknesses and cross-sectional areas were significantly reduced in both groups, but the reductions were significantly more substantial in group II than in group I. The intergonial width of the mandibular angle area did not change significantly in either group. However, the bone volume of the mandibular gonial angle area was more significantly reduced in group II than in group I. Conclusions: The repeated administration of BoNT-A injections may induce bone volume changes in the mandibular angle area.

• The Journal of the Korean dental association
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• v.56 no.4
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• pp.208-216
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• 2018

Patients with malocclusion may present with preexisting mucogingival problems susceptible to attachment loss during or after orthodontic treatment. Lower anterior teeth especially show a high prevalence of gingival recession following orthodontic treatment. This case report demonstrates hard tissue augmentation of labially thin or deficient alveolar bone (dehiscences and fenestrations) to prevent attachment loss during or after orthodontic treatment. Three patients presented clinically prominent root surfaces and dehiscences and fenestrations on cone-beam computed tomography (CBCT) in lower anterior teeth. Labial hard tissue augmentation of lower anterior teeth was performed with deproteinized bovine bone mineral and collagen membrane. Six months later, hard tissue augmentation reduced root prominence and created a greater volume of hard tissue on lower anterior area in clinical and radiographic findings. Hard tissue augmentation using xenograft could prevent attachment loss associated with orthodontic treatment and maintain stability of healthy periodontium.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.399-402
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• 2003

A female unknown aged Yorkshire terrier, weighing 3.5 kg with nasal discharge, left facial swelling and severe inflammation was referred to Veterinary Medical Teaching Hospital, Seoul National University. Radiographic findings were lytic change and soft tissue swelling of left zygomatic process and increased radiopacity of nasal cavity. In computed tomography, turbinate bone destruction was observed as well as lytic change of left zygomatic process and left maxilla indicating aggressive lesion. Then 3-dimensional reconstruction was also performed. Biopsy of tissue mass revealed it as squamous cell carcinoma. For this patient, euthanasia was performed guarded prognosis. Generally, tumors of the nasal cavity in dogs account for approximately 1 % to 2% of all neoplasms. The prevalence of these tumors increased with age and exposure to the ultraviolet. About two thirds of all nasal tumors are malignant tumors such as squamous cell carcinoma and adenocarcinoma. As these tumors of nasal cavity are locally invasive, and external beam radiotherapy is the current treatment of choice. Unfortunately, diagnosis of these tumors often occurs late in the course of disease, resulting in a poor prognosis for outcome in many patients. It is considered that computed tomography could be used as an aid modality for the exact evaluation of extend and degree of bone lysis of nasal cavity and metastasis.

• Journal of Periodontal and Implant Science
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• v.51 no.4
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• pp.239-253
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• 2021

Purpose: The single-flap approach (SFA) is a minimally invasive technique with limited mucoperiosteal flap elevation to gain access to the buccal/palatal aspects, thus limiting post-surgical complications. The purpose of the present study was to gain insights into the impact of the SFA over the double-flap approach (DFA) on periodontal flap treatment outcomes and patient compliance in terms of discomfort and time taken for surgical procedures. Methods: Twenty patients with persistent probing pocket depths of ≥5 mm were scheduled for the SFA (test site) and for the DFA (control site). All the clinical periodontal parameters were recorded at baseline, 3 months, and 6 months. Radiographic bone level (cone-beam computed tomography) was evaluated at baseline and 6 months. Patients' postoperative pain perception and wound healing were also assessed. Results: The SFA showed a significant reduction in periodontal pocket depth, gain in clinical attachment level (CAL), and gain in bone level when compared with the DFA. The SFA substantially improved wound healing and induced less postoperative pain than the DFA. Conclusions: The SFA resulted in substantial improvement in the composite outcome measures, as shown by a reduction in pocket depth with minimal gingival recession, gain in CAL, early wound healing, less postoperative discomfort, and better patient-centered outcomes.

• Imaging Science in Dentistry
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• v.52 no.3
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• pp.319-326
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• 2022

This report presents the case of a 5-year-old boy with a hard swelling on the right side of the mandible body. An important point of this case is that the primary imaging finding was fine spicules in the inferior border of the mandible on panoramic radiography without significant changes in bone density. Cone-beam computed tomography views revealed a lytic lesion on the lingual side of the right mandibular body with the destruction of the lingual cortex and periosteal reaction from the midline to the first molar area. Careful attention to this radiographic finding in the primary stage in the absence of other significant imaging findings, particularly in children, could result in the early diagnosis of desmoplastic fibroma. Therefore, a better prognosis can be expected following early surgical treatment.